|CD4+ counts||Alternative causes of depletion||Non physical stress||Pregnancy|
|Changes in CD4 and CD8 cell levels during pregnancy and post partum in women seropositive and seronegative for HIV-1.|| ||Burns DN, Nourjah P, Minkoff H, et al.
| ||The authors attempted to control for potentially confounding factors like the increased blood volume that normally occurs in pregnancy. They used CD4 percentages because of this variable, and determined that "Our CD4 cell findings for HIV-negative women are consistent with the majority of prior studies, which demonstrate a decline in CD4 levels during normal pregnancy".|
| ||Am J Obstet Gyn, 1996, 174(5); 1461-1468||1996|
|Decreased levels of circulating CD4+ T lymphocytes during normal human pregnancy.|| ||Castilla JA, Rueda R, Vargas L, et al.
| ||A study of normal pregnancy found reduced CD4 percentages in the 1st and 2nd trimester, as well as reduced CD4/CD8 ratios in the 2nd trimester Comment on previous studies looking at a variety of lymphocyte changes during pregnancy : "In these studies, variation in the number and proportion of CD4+ lymphocytes is the alteration most frequently reported".|
| ||J Reprod Immuno, 1989; 15; 103-111||1989|
|Decreased levels of helper cells: A possible cause of immunodeficiency in pregnancy.|| ||Sridama V, Pacini F, Yang S, et al.
| ||These researchers found reduced absolute CD4 counts, as well as reduced percentages of CD4+ T-cells in 76 women with normal pregnancies. By the third trimester, the pregnant women had an average of only 543 + 169 CD4+ T-cells, compared to 1073 + 441 in non-pregnant women who served as controls. Both the absolute numbers and the percentages stayed low until several months post-partum, and similar results were obtained for the CD4/CD8 ratio which was also reduced.|
| ||New Eng J Med, 1982, 307(6); 352-356||1982|